The Cytogenetics Core Facility provides classic cytogenetics, molecular cytogenetics, and molecular clonality support services. Specific core services include: cell line verification and characterization, cell culturing, solid tumor cytogenetics, 24-color karyotyping, clonality (HUMARA) testing, consultation services, a reference laboratory for the Southwest Oncology Group (SWOG) leukemia/solid tumor cytogenetics program, molecular cytogenetics and imaging analysis training, fluorescence photomicroscopy, and various fluorescence in situ hybridization (FISH) studies for aneuploidy detection, gene tracking, zygosity status, specific genetic alterations, and gene integration/mapping studies. T-FISH or tyramide signal amplification FISH is used for cellular localization of nucleic acids when target levels are suspected to be low (e.g., gene or adoptive immunotherapy studies). Recently added services included spectral FISH, a technique that allows for the simultaneous detection of 3-10 DNA probes in a single hybridization, the combined immunophenotype/genotype method known as FICTION or fluorescence immunophenotyping and interphase cytogenetics as a tool for investigation of neoplasms, microsatellite instability testing and quantitative PCR services for NCI-approved investigations utilizing genetically modified cells. Major accomplishments of this core fall into three general categories: 1) improved diagnostic, prognostic and therapeutic monitoring; 2) contributions to a better understanding of neoplastic disorders; and 3) a productive translational bridge between clinicians and basic science researchers. The value-added features include cost effectiveness, on site expertise, rapid turnaround time, quality assurance, data security, and training/education. Peer-reviewed usage of this core by Cancer Center members is 91.3% of the total usage.